Silver halide photographic emulsion

ABSTRACT

A SILVER HALIDE PHOTOGRAPHIC EMULSION CONTAINING AT LEAST ONE SENSITIZING DYE REPRESENTED BY THE FOLLOWING GENERAL FORMULA I AND AT LEAST ONE SENSITIZING DYE REPRESENTED BY THE FOLLOWING GENERAL FORMULA II:   Z1&lt;(-(4-(HOOC-)-1,2-PHENYLENE)-N(+)(-R1)=C(-CH-C(-C2H5)-   CH=C&lt;(-Z2-(4-N-1,2-PHENYLENE)-N(-R2)-))-)   WHEREIN Z1 AND Z2, WHICH MAY BE THE SAME OR DIFFERENT, ARE SULFUR OR SELENIUM ATOMS; R3 IS HYDROGEN OR ALKYL HAVING FROM 1 TO 4 CARBON ATOMS; W IS HYDROGEN, HALOGEN, AN ALKYL GROUP HAVING FROM 1 TO 4 CARBON ATOMS, ALKOXY, HYDROYL, OR ARYL; R1 AND R2, WHICH MAY BE THE SAME OR DIFFERENT, ARE ETHYL, N-PROPYL, $-SULFOPROPYL, $-SULFOBUTYL, 8-SULFOBUTYL, OR VINYLMETHYL GROUPS WITH THE PROVISO THAT R1 AND R2 MAY NOT SIMULTANEOUSLY BE SULFOALKYL GROUPS SELECTED FROM THE GROUP CONSISTING OF $-SULFOPROPYL, $-SULFOBUTYL AND 8-SULFOBUTYL GROUPS, AT LEAST ONE OF R1 AND R2 BEING $-SULFOPROPYL, $-SULFOBUTYL OR 8-SULFOBUTYL WHEN R3 IS AN ALKYL GROUP HAVING FROM 1 TO 4 CARBON ATOMS; X1$ IS AN ANION AND N IS 0 OR 1, N BEING 0 WHEN AN INTRAMOLECULAR SALT IS FORMED; AND   Z3&lt;(-(1,2-PHENYLENE)-N(+)(-R4)=C(-CH=C(-CH3)-CH=C&lt;(-Z4-   (1,2-PHENYLENE)-N(-R5)-))-)   WHEREIN Z3 AND Z4, WHICH MAY BE THE SAME OR DIFFERENT, ARE SULFUR OR SELINIUM ATOMS; R4 AND R5, WHICH MAY BE THE SAME OR DIFFERENT, ARE ALKYL GROUPS HAVING FROM 1 TO 4 CARBON ATOMS, SULFOALKYL GROUPS, CARBOXYALKYL GROUPS OR ALLYL GROUPS; X2$ IS AN ANION; AND N IS 0 OR 1, N BEING 0 WHEN AN INTRAMOLECULAR SALT IS FORMED.

United States Patent Oflice 3,681,080 Patented Aug. 1, 1972 rm. (:1. misc 1/08 US. Cl. 96-124 17 Claims ABSTRACT OF THE DISCLOSURE A silver halide photographic emulsion containing at least one sensitizing dye represented by the following general Formula I and at least one sensitizing dye represented by the following general Formula II:

R1 (X1 wherein Z and Z which may be the same or different, are sulfur or selenium atoms; R; is hydrogen or alkyl having from 1 to 4 carbon atoms; W is hydrogen, halogen, an alkyl group having from 1 to 4 carbon atoms, alkoxy, hydroxyl, or aryl; R and R which may be the same or difierent, are ethyl, n-propyl, 'y-sulfopropyl, 'y-sulfobutyl, 6-sulfobutyl, or vinylmethyl groups with the proviso that R and R may not simultaneously be sulfoalkyl groups selected from the group consisting of 'y-sulfopropyl, 'y-sulfobutyl and fi-sulfobutyl groups, at least one of R and R being -sulfopropyl, 'y-rsulfobutyl or a-sulfobutyl when R;, is an alkyl group having from 1 to 4 carbon atoms; X is an anion and n is or 1, n being 0 when an intramolecular salt is formed; and

R4 a h wherein Z and 2,, which may be the same or diiferent, are sulfur or selinium atoms; R, and R which may be the same or difierent, are alkyl groups having from 1 to 4 carbon atoms, sulfoalkyl groups, carboxyalkyl groups or allyl groups; X is an anion; and n is 0 or 1, nbeing 0 when an intramolecular salt is formed.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a silver halide photographic emulsion, in particular, an emulsion supersensitized by using a combination of two different types of sensitizing dyes, and more particularly, it is concerned with a silver halide photographic emulsion having a high red sensitivity, wherein the spectral sensitization maximum is within a range of 625-660 m,u.

Description of the prior art It is well known in techniques of making siliver halide photographic emulsions that the addition of a sensitizing dye to a silver halide emulsion results in an enlargement of the sensitive wavelength region thereof as well as its optical sensitization. In photographic materials, one kind of sensitizing dye is used in order to sensitize a desirable spectral sensitization wavelength region, but, in many cases, two or more kinds of sensitizing dyes are used in combination.

The spectral sensitization in the case of using two or more sensitizing dyes is generally less than in the case of using each of the sensitizing dyes above, but the use of ditferent types of sensitizing dyes in combination, in some cases, produces a remarkable rise in the spectral sensitization as compared with the case of using each of them individually. This phenomenon is called supersensitization of the sensitizing dyes. Sometimes the sensitization wavelength region falls in between these regions when the dyes are individually used.

In techniques of making silver halide photographic emulsions, it is customary to use two or more different types of sensitizing dyes in combination so that a desired spectral sensitization wavelength region may be sensitized, a higher spectral sensitization than occurs when using them individually may be obtained through their interaction and the spectral sensitization wavelength region may be adjusted to a desired sensitization wavelength region.

Therefore, it is important in the field of spectral sensitization to find such a combination of sensitizing dyes in order to obtain a higher spectral sensitivity through the use of the combination than when using the sensitizing dyes individually, and to adjust the sensitization wavelength region of photographic materials; that is to say, in a supersensitization relation.

It is the principal object of the present invention to provide a silver halide photographic emulsion having a high red sensitivity over a spectral sensitization wavelength region of 625-660 mg by the use of two different types of sensitizing dyes in combination.

SUMMARY OF THE INVENTION The principal object of the present invention can be accomplished by incorporating in a silver halide photographic emulsion sensitizing dyes represented by the following general Formulae I and II, in combination:

General Formula I wherein: Z, and Z which may be the same or different, are either sulfur or selenium atoms; R is hydrogen or a lower alkyl group such as methyl or ethyl: W is hydrogen, halogen (such as chlorine or bromine), a lower alkyl group .(such as methyl or ethyl group), alkoxy (such as methoxy or ethoxy), hydroxyl or aryl (such as phenyl); R and R which may be the same or dilferent, are ethyl, n-propyl, -sulfopropyl, 'y-sulfobutyl, a-sulfobutyl or vinylmethyl groups with the proviso that R and R may not simultaneously be sulfoalkyl groups selected from the group consisting of 'y-sulfopropyl, 'y-sulfobutyl and E-sulfobutyl groups, at least one of R and R being 'y-sulfopropyl, -sulfobutyl or a-sulfobutyl group when R, is a lower alkyl group; X is an anion such as halogen, perchlorate, thiocyanate, benzene-sulfonate, ethylsulfate, ptoluenesulfonate, methylsulfate, and the like; and n is 0 or 1, n being 0 when an intramolecular salt is formed.

General Formula II on, j x

R4 (X2 it,

wherein: Z, and 2,, which may be the same or diiferent,

are either sulfur or selenium atoms; R; and R which may be the same or different, are lower alkyl groups (such as methyl and ethyl), substituted alkyl groups (such as sulfoalkyl and carboxyalkyl) and allyl groups (such as vinylmethyl); X is an anion such as halogen, perchlorate, thiocyanate, benzenesulfonate, ethylsulfate, p toluenesulfonate, methylsulfate, and the like; and n is or 1, n being 0 when an intramolecular salt is formed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It has been found that the use of sensitizing dyes represented by Formulae I and II in combination gives a remark-able supersensitizing efiect and a high red sensitivity over a spectral sensitization wavelength region of 625 660 m Furthermore, the sensitizing dyes of the present invention are available for general black-and-white high sensitivity photographic materials since the combination eifect of the sensitizing dyes represented by Formulae I and II according to the present invention is not afl ected by the further addition of a known green-sensitive sensitizing dye.

The following typical examples of the sensitizing dyes of the present invention are merely illustrative, and not limiting in nature.

(D-A S CH OOC (I)B 02115 S 011,0 oo o/ N I cum-0 rr-ona I (CHzMSkh C11 0 0G Cl I o 1.120 H2O H3 dnmsoa 02H5 on?) 1s0i cilia HOHC- iiggg M.P.( o.) (I)-G /S (32115 S\ \N I9 I? -oH=o c-n= o 0- 69 -01:

\N N/ C2115 2H5 (11-1 s s CH=CCII= I on 000 ea OH 3 N/ zh a 2 5 (DJ 01m I CH=C-CH 0113000- N/ l Cums 05 outs (U-K /S CZHE S -oH=o-oH= HOOG- N/ on;

AMeOH M.P.( o. (D-L /S (32115 S\ I -o1r=o cr-r= o rr ooc \g? N/ 00111 I e (CHmS O3 2H5 550 more than 300 -o11=o-on= 11000 g N/ -o1 l I (CHnoHcm Gin-0111:0115

(I)-N s CzHE s -CH=CCI-I= CH3OOC g N/ -01 I ($11515 05 CH -CH=OHz I CZH5 lHzcHz Ha ((EHzh a The sensitizing dyes used in the present invention can readily be synthesized by suitable methods known to those skilled in the art, for example, the methods disclosed in US. Pats. Nos. 2,647,051 and 2,503,776 and German Pats. Nos. 929,080 and 1,072,765.

The method of spectral sensitization according to the present invention is suitable for the spectral sensitization of not only gelatino-silver halide emulsions but also emulsions containing a hydrophilic colloid other than gelatin, for example, agar, water-soluble cellulose derivatives, polyvinyl alcohol and other synthetic or natural hydrophilic resins. As the emulsion useful in the present invention, a mixed silver halide emulsion such as silver iodobromide or silver chloroiodobromide is preferably used. Preparation of a spectrally sensitized photographic emulsion according to the present invention may be carried out by incorporating the sensitizing dyes (I) and (II) in a photographic emulsion in a conventional manner. Ordinarily, the dyes are added to an emulsion in the form of a solution in a suitable solvent such as methanol or ethanol. 1

The molar ratio of sensitizing dye (I) to dye (II), incorporated in an emulsion, may be varied within a wide range of from 9:1 to 1:9, depending on the desired effect.

The photographic emulsion of the present invention may be subjected to hypersensitization, as well as supersensitization, in any known manner. In the preparation of the photographic emulsion of the present invention, commonly used additives, for example, sensitizers, stabilizers, color tone regulators, hardeners, surfactants, fog inhibitors, plasticizers, development accelerators, color formers and fluorescent whitening agents may be added to the emulsion in any conventional manner.

The photographic emulsion of this invention may be applied in any conventional manner to a suitable support such as a glass sheet, a cellulose derivative film, a synthetic resin film or a baryta paper.

The following examples are given in order to further illustrate the present invention in detail, and are deemed to be illustrative, rather than limiting, in nature.

EXAMPLES To a silver iodobromide emulsion (AgI:AgBr=5.5 mols: 94.5 mols) was added sensitizing dye (I) or (II) individually to prepare silver halide photographic emulsions. Other silver halide photographic emulsions were prepared by incorporating in the emulsion sensitizing dyes (I) and (II) in combination, optionally with a known green-sensitive sensitizing dye. The resulting emulsions TABLE 1 Metol 2 Sodium sulfite 100 I-Iydroquinone 5 Borax 2 Water to make 1000 ml.

In Table 2 are shown the spectral sensitivity and sensitization maximum in the case of adding sensitizing dye (I) only. In Table 3 are shown the spectral sensitivity and sensitization maximum in the case of adding sensitizing dye (II) only. In Table 4 are shown the spectral sensitivity and sensitization maximum in the case of adding the typical sensitizing dyes selected from sensitizing dyes (I) and (II) in combination. In Table 5 are shown the spectral sensitivity and sensitization maximum in the case of using sensitizing dyes (I) and (II) with known greensensitive sensitizing dyes A or B in combination.

TABLE 2 Amount of dye added Sensitization (mg mol/kg maximum Red Dye No emulsion) Emulsion (mm.) sensitivity 0.02 AgBr/I 632 0.02 .AgBr/I 632 88 0.04 AgBr/I 632 120 0.06 AgBr/I 645 88 0.04 AgBr/I 632 0.04 AgBr/I 655 0.04 AgBr/I 652 95 0.06 'AgBr/I 644 0.04 AgBr/I 648 230 0.06 AgBr/I 635 38 0.06 AgBr/I 648 320 0.06 AgBr/I 652 330 0.08 AgBr/I 656 95 0.08 AgBr/I 645 40 The red sensitivity is shown by the relative sensitivity to that of sensitizing dye II-6 being 100 when exposed using a Fuji N0. 7 Filter (red filter).

The red sensitivity is shown by the relative sensitivity to that of sensitizing dye II-6 being 100 when exposed using a Fuji No. 7 Filter (red filter).

TABLE 4 Amount of dye added Sensitization (mg. mol/kg. maximum Red emulsion) Emulsion (mm.) sensitivity as: net e2 0.02 AgBr/I 640 240 0.04 AgBr/I 655 110 0.06 AgBr/I 628 140 0.02 AgBr/I 655 213 0.06 AgBr/I 630 04 0.02 AgBr/I 654 146 0. 04 AgBr/I 652 95 0.06 AgBr/I 616 100 0.03 AgBr/I 648 140 0.02 AgBr/I 632 83 0.06 AgBr/I 630 187 0.01 AgBr/I 632 263 0.06 AgBr/I 638 130 0.01 AgBr/I 040 150 0.06 AgBr/JI 635 38 0.02 AgBr/I 035 205 0.04 AgBr/I 632 120 0.01 AgBr/I 032 263 0.06 AgBr/I 648 320 0.04 AgBr/I 645 360 0.06 AgBr/I 652 330 0.06 .AgBr/I 625 140 0.06 AgBr/I 652 380 The red sensitivity is shown by the relative sensitivity to that of sensitizing dye 11-6 being 100 when exposed using 21 Fuji No. 7 Filter (red filter).

TABLE 5 Amount of emulsion) Emulsion (111111.) sensitivity 0.06 AgBr/I 644 170 0.06 AgBr/I 630 187 0.04 AgBr/I 644 225 0.04 AgBr/I 044 225 0.04 AgBr/I 632 10 0.06 AgBr/I 616 10 0.02 AgBr/I 640 130 0.02 AgBr/l'. 640 130 0. 04 AgBr/I 648 230 0.02 AgBr/I 642 255 0.02 AgBr/I 642 255 0.08 AgBr/I 056 0.02 AgBr/I 630 225 0.08 AgBr/I 645 40 0.02 AgBr/I 640 250 The red sensitivity is shown by the relative sensitivity to that of sensitizing dye II-6 being when exposed using 2. Fuji No. 7 Filter (red filter).

As is evident from Table 4, the red sensitivity is raised in the case of using sensitizing dyes (I) and (II) in com bination much more than in the case of using sensitizing dye (I) or (II) individually. As is evident from Table 5, the combination elfect of sensitizing dyes (I) and (II) is not affected by the further addition of a known greensensitive sensitizing dye, for example, A or B (shown below).

Such known green-sensitive sensitizing dyes used in combination with sensitizing dyes (I) and (II) have, for example, the following chemical structures:

Dyes I and II may be added to the emulsion in an amount of from 0.008 to 0.4 mg. mole per kg. of emulsion.

What is claimed is:

1. A silver halide photographic emulsion containing at least one sensitizing dye represented by the following general Formula I and at least one sensitizing dye represented by the following general Formula H:

wherein Z, and Z which may be the same or different, are sulfur or selenium atoms; R is hydrogen or alkyl having from 1 to 4 carbon atoms; W is hydrogen, halogen, an alkyl group having from 1 to 4 carbon atoms; alkoxy, hydroxyl, or aryl; R; and R which may be the same or difierent, are ethyl, n-propyl, -sulfopropyl, 'y-sulfobutyl, a-sulfobutyl, or vinylmethyl groups with the proviso that R and R may not simultaneously be sulfoalkyl groups selected from the group consisting of -sulfopropyl, -sulfobutyl and a-sulfobutyl groups, one of R and R being 'y-sulfopropyl, -sulfobutyl or 6-sulfobutyl when R is an alkyl group having from 1 to 4 carbon atoms; X is an anion and n is or 1, n being 0 when an intramolecular salt is formed; and

RzOOC wherein Z;, and Z which may be the same or different, are sulfur or selenium atoms; R and R which may be the same or different, are alkyl groups having from 1 to 4 carbon atoms, sulfoalkyl groups, carboxyalkyl groups or allyl groups; X is an anion; and n is 0 or 1, n being 0 when an intramolecular salt is formed.

2. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

nais i 0211,

and

CH=i OH= ii elm Br ormaooorr 3. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

ohms 0, 5119200011 4. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

s z 5 s GH=ZZH \fQi/ \N HOOC C1 and Kall S\ \g/ mon=cm Br enion=onz 5. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae \I and II are, respectively,

onmso 3211,

and

Se 3 orhh-on \ffi/ \N/ omomorn onmsoi 6. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

/s\ Elm CH: -CH'* \i'i/ 023, Br 2H5 7. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

and

9. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are,

and

10. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

11. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

mns s cal-when,

and

/ 1Hz -=C H=C C H:

12. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

2 5 CH=(i -CH= HaCOOC- g N 12 13. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

02H: S -on=e crr= CHaOOC- g 111 14. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

and

C 11:41 C H: e/ \N N/ 2115 (drmlsol 15. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are, respectively,

and

16. A silver halide photographic emulsion as in claim 1 wherein said dyes represented by Formulae I and II are,

respectively,

S 2115 j CH=(|JCH omooO- g/ (:1 (315M03 drrzorncn and 13 14 17. A photographic light-sensitive element comprising 3,527,641 9/1970 Nakazawa et a1. 96124 2, support having thereon at least one layer containing the 3,573,920 4/ 1971 Hillel 96124 photographic silver halide emulsion as in claim 1. OTHER REFERENCES 5 Serial #57,607, filing date July 23, 1970, by Shiba et References Cited 1 UNITED STATES PATENTS NORMAN G. TORCHIN, Primary Examiner 3,463,640 8/1969 Ficken et a1. 96-124 KIMLIN Assistant Examiner 3,459,553 8/1969 Walworth 96124 10 us. Cl. XIR.

3,338,714 8/1967 Ficken et a1 96-124 

